US officials today played down claims that the appeal court's disclosure of CIA information passed to MI5 will damage intelligence-sharing with Britain as fresh doubts emerged about the accuracy of information given to MPs.

A White House official, speaking on condition of anonymity, said the court decision would not provoke a broad review of intelligence liaison between Britain and the US because the need for close co-operation was greater now than ever.

In addition, Gary Berntsen, a former senior CIA officer who served in the Middle East, said the two countries' intelligence services would continue to co-operate, regardless of the court order.

"The relationship between us and the British is probably the strongest relationship in the world," he said. "Neither intelligence service would like the judicial system interfering. The people of the US and especially the officers in the agency are grateful for the UK, grateful for our colleagues in MI5 and MI6. These relationships, they have saved Americans on many many occasions."

Earlier, Dennis Blair, US director of national intelligence, condemned the court decision, saying it was "not helpful, and we deeply regret it". He added: "This court decision creates additional challenges, but our two countries will remain united in our efforts to fight against violent extremist groups."

White House spokesman Ben LaBolt said the US was "deeply disappointed" in the court judgment. "We shared this information in confidence and with certain expectations," he said. "The court'sjudgment will complicate the confidentiality of our intelligence-sharing relationship with the UK".

He added: "This just means that we need to redouble our efforts to work through this challenge, because the UK remains a key partner in our collective efforts to suppress terrorism and other threats to our national security."

In a joint letter to the Guardian tomorrow, David Miliband, the foreign secretary, and Alan Johnson, the home secretary, say that guidance to British security and intelligence officers changed after the 9/11 attacks on the US "to make clear their responsibilities not just to avoid any involvement or complicity in unacceptable practice, but also to report on them".

MI5 subsequently told the parliamentary intelligence and security committee that British resident Binyam Mohamed was interrogated "in line with the service's guidance to staff on contact with detainees".

However, a seven-paragraph summary released by the appeal court shows that the CIA told MI5 that Mohamed had been subjected to "continuous sleep deprivation ... threats and inducements". It is described as "at the very least inhuman and degrading treatment of BM by the United States authorities".

The appeal court's judgment refers to evidence that MI5 officers continued to help Mohamed's US interrogators even after they were passed detailed accounts of his mistreatment. An MI5 officer, known as Witness B, interviewed Mohamed incommunicado in 2002.

Reprieve, the legal charity which represents Mohamed, said : "The foreign and home secretaries' letter suggests ... a whistle ought to have been blown by British agents. Rather, MI5 continued to feed questions to Binyam's torturers. If a system for reporting torture was indeed place, it was a disastrous failure".

Lawyers for Mohamed, the Guardian and other media organisations, the civil rights groups Liberty and Justice, and Index on Censorship will today send representations to Lord Neuberger, the master of the rolls, urging him to reinstate comments he made about MI5's behaviour in his draft judgment but omitted after complaints by the government's lawyer, Jonathan Sumption QC.